LED Lamp With A High Color Rendering Index

Abstract

LED lamps having a high color rendering index are disclosed. In some embodiments, such lamps also exhibit high lumen maintenance and low color drift during lamp warm-up. The lamps may include, for example, a light emitting diode (LED) kernel having a mixture of red and blue LEDs, and a converter including a red phosphor in an amount ranging from greater than 0 to about 10 weight % of a total phosphor content of the converter.

Description

FIELD OF THE INVENTION[0001]The present application relates to light sources with a high color rendering index (CRI) and, more particularly, to light emitting diode (LED) lamps with a high color rendering index.BACKGROUND OF THE INVENTION[0002]Solid state light sources such as light emitting diodes (LEDs) generate visible or non-visible light in a specific region of the electromagnetic spectrum. An LED may output light, for example, in the blue, red, green or non-visible ultra-violet (UV) or near-UV regions of the electromagnetic spectrum, depending on the material composition of the LED. When it is desired to construct an LED light source that produces a color different from the output color of the LED, it is known to convert the LED light output having a peak wavelength (“primary light”) to light having a different peak wavelength (“secondary light”) using photoluminescence.[0003]Photoluminescence generally involves absorbing higher energy primary light by a converter including a ...

AI Technical Summary

Benefits of technology

The patent text describes a method for producing light sources with a high color rendering index (CRI) using phosphor converted white LED lamps. The technical effect of this invention is to provide light sources that produce a high quality color rendering, similar to natural light sources, using phosphor conversion technology. The invention also addresses issues with existing solutions such as color shifting, poor lumen maintenance, and complex driving circuitry. The patent text describes the use of converters that take the form of a self-supporting plate or a thin film to convert primary light to secondary light. The converter may be attached directly to the LED or may be positioned remotely from the LED. The invention also discusses the use of different phosphor configurations for achieving high CRI values. The patent text includes a diagrammatical representation of the different configurations and their spectral power distribution. The technical effect of this invention is to provide light sources with a high CRI that can produce a high-quality color rendering, similar to natural light sources, using phosphor conversion technology.

Problems solved by technology

Although several known phosphor converted white LED lamps with high CRI exist, these existing solutions may exhibit significant color shift, poor lumen maintenance and / or require the use of complex driving circuitry.

Such issues may limit the usefulness and commercial viability of such lamps.

Images